Method and apparatus for drying organic materials

ABSTRACT

In a method for drying a material at least mainly consisting of organic substances such as carbohydrates and proteins, using a drum drier as to dry said material thereon, the improvement that said material is heated to a temperature at which its constituents are liquid, and is applied in said liquid state to the drying drum of said drum drier. Preferably, said material includes additives such as alkalis, acids or enzymes.

llnited States Patent Fritze et a]. 5] May 23, 1972 [54] METHOD ANDAPPARATUS FOR [56] References Cited DR G ORG C UNITED STATES PATENTS[72] Inventors g m zg x f 1,250,427 12/1917 Campbell ..34/12 x y1,240,816 9/1917 Brownell [73] Assignee: Escher Wyss GmbH, Ravensburg,

Wurthemberg, Germany Primary Examiner-John J. Camby 22 Filed: Aug. 11,1970 Osman [21] App1.No.: 62,904 ABSTRACT In a method for drying amaterial at least mainly consisting of [30] Foreign Application PriorityDat organic substances such as carbohydrates and proteins, using a drumdrier as to dry said material thereon, the improvement Aug. 14, 1969Germany ..P 19 41 425.6 that said material i heated to a temperature atwhich is com stituents are liquid, and is applied in said liquid stateto the [52] US. Cl ..34/l2, 34/60 drying drum of Said drum drien P f bli material [5 1] Int. Cl ..F26b 7/00 eludes additives Such as alkalisacids enzymes. [58] Field of Search ..34/12, 17, 60

11 Claims, 1 Drawing figure Patented May 23, 1972 BACKGROUND OF THEINVENTION The invention relates to a method for drying a material atleast mainly consisting of organic substances such as carbohydrates andproteins, wherein there are optionally admixed with these substancesadditives such as alkalis, acids or enzymes, and the material is driedon a drum drier, and to an apparatus for carrying out this method.

In a known process for drying casein, dilute caustic soda solutionhaving a high water content is admixed, as additive, with the casein(lactic acid casein) coming from the cheese factory. The casein is mixedwith the additive and the mixture is then dried on a drum drier. Thisprocess has the disadvantage that relatively large quantities of watermust be evaporated on the drum drier and that the drying does not yieldan entirely uniform end product.

SUMMARY OF THE INVENTION The invention has for its object to reduce thequantity of water which must be evaporated from the drum drier in thedrying of a material at least mainly consisting of organic substancessuch as carbohydrates and proteins, and to obtain a more uniform endproduct. In the method described at the beginning, this object isachieved in accordance with the invention by virtue of the fact that thematerial is heated to a temperature at which its constituents areliquid, and is fed in this liquid state to the drying drum of the drumdrier.

Advantageously, the method is employed for drying casein, moreespecially lactic acid casein, with which additives such as caustic sodasolution or sodium carbonate solution are admixed, and the mixture, i.e.the ratio of casein to additives, is made such that the pH-value of thematerial is between 6.7 and 7.0. The temperature at which the materialthen becomes liquid, at these pH-values, is between about 100 and 120 C.

BRIEF DESCRIPTION OF THE DRAWING An apparatus for carrying out themethod of the invention is illustrated in simplified form in thedrawing, with reference to which the process of the invention will bemore particularly described by way of example as applied to casein.

DESCRIPTION OF THE PREFERRED EMBODIMENT The illustrated apparatuscomprises a heatable drying drum 1 which is preceded by a device 2 formixing the substances to be dried and the additives. An applicator 3serves to apply the material to the drying drum 1. The mixing device 2comprises a supply duct 4 for the substances, i.e., the casein, and asupply duct 5 for the additives. A control device 6 is provided by meansof which, with the aid of regulating devices not shown, (for examplerotary valves or throttle valves), which are provided in the ducts 4 and5, the quantities passing through the ducts 4 and 5 per unit time can becontrolled.

A motor 7 drives a mixing screw 8 in the mixing device 2. A scraper 9 isprovided to detach the dried end product from the drying drum 1. Thedetached product is carried away on a conveyor belt 10.

Provided between the mixing device 2 and the applicator 3 is a heatingdevice 11. The casein coming from the cheese factory and fed through theduct 4, and the additives fed through the duct 5, which are to be driedon the drying drum 1 of the drum drier after having been mixed in themixing device 2, are thus heated in the heating device 11, before beingapplied to the drying drum 1, to a temperature at which the constituentsof the material are liquid and the material is applied in this liquidstate to the drying drum 1.

In this way, a good reaction of the substances is obtained by theconversion into the molten state before the material is applied to thedrying drum 1. The drier merely has to perform the drying of acompletely prepared wet material. Consequently, the water content of thewet material can be kept very low, and it IS merely necessary toevaporate out small quantities of water.

In addition to the better utilization of the heating surface of thedrier and the better heat economy, the process of the invention has thefurther advantage that the material applied to the drying drum in themolten state is very uniformly distributed in the wet material andyields a correspondingly uniform end product. The more uniform qualityof the end product ensures, for example, in the case of casein, betterforce of adhesion and better water-combining capacity at low and hightemperatures.

The addition of chemicals is also easier with the molten substances, orwith the molten mixture, and can be more readily controlled.

The heating device 11 is constructed as a device for the directintroduction of steam into the material, the substances or theadditives. The mixture flows through a tube-like duct 12 which isconstructed in the form of a noule. In that section of the nozzle-formduct 12 in which the cross-section widens, vapor-supply channels 13 areprovided, which open into the duct 12 substantially perpendicularly tothe axis of the latter. The steam is supplied to the channels 13 througha duct 14 and a jacket 15 surrounding the duct 12.

A particularly thick layer of the molten material can be obtained on thedrying drum 1 by the illustrated construction of the applicator 3 as acylinder.

We claim:

1. A method for drying a material, consisting at least mainly of organicsubstances such as carbohydrates and proteins, using a drum drier, andcharacterized in that said material is heated to a temperature at whichits constituents are liquid by the direct application of steam thereto;and the material in said liquid state is then applied to the drum ofsaid drier.

2. A method as defined in claim 1 in which said material includesadditives such as alkalis, acids or enzymes.

3. A method as defined in claim 2 in which said material consists mainlyof casein and contains, as an additive, a caustic soda solution.

4. A method as defined in claim 3 in which the casein is lactic acidcasein.

5. A method as defined in claim 2 in which said material consists mainlyof casein and contains, as an additive, a sodium carbonate solution.

6. A method as defined in claim 5 in which the casein is lactic acidcasein.

7. A method as defined in claim 2 in which the ratio of said substancesto said additives is such that the pH value of said material is between6.7 and 7.0.

8. Apparatus for drying a material consisting at least mainly of organicsubstances such as carbohydrates and proteins comprising a heatabledrying drum, an applicator arranged to apply the material to the drum,and means for feeding the material to the applicator, and characterizedby a heating device incorporated in the feeding means and serving toraise the temperature of the material to a level at which itsconstituents are liquid, the device including means for directlyintroducing steam into the material.

9. Apparatus as defined in claim 8 in which the feeding means includes amixing device for admixing additives with said substances.

10. Apparatus as defined in claim 8 in which said heating devicecomprises a tube-like duct for said material which has a wideningcross-section; and supply channels for the steam which opensubstantially perpendicularly into the duct.

11. Apparatus as defined in claim 8 in which said applicator is acylinder.

2. A method as defined in claim 1 in which said material includesadditives such as alkalis, acids or enzymes.
 3. A method as defined inclaim 2 in which said material consists mainly of casein and contains,as an additive, a caustic soda solution.
 4. A method as defined in claim3 in which the casein is lactic acid casein.
 5. A method as defined inclaim 2 in which said material consists mainly of casein and contains,as an additive, a sodium carbonate solution.
 6. A method as defined inclaim 5 in which the casein is lactic acid casein.
 7. A method asdefined in claim 2 in which the ratio of said substances to saidadditives is such that the pH value of said material is between 6.7 and7.0.
 8. Apparatus for drying a material consisting at least mainly oforganic substances such as carbohydrates and proteins comprising aheatable drying drum, an applicator arranged to apply the material tothe drum, and means for feeding the material to the applicator, andcharacterized by a heating device incorporated in the feeding means andserving to raise the temperature of the material to a level at which itsconstituents are liquid, the device including means for directlyintroducing steam into the material.
 9. Apparatus as defined in claim 8in which the feeding means includes a mixing device for admixingadditives with said substances.
 10. Apparatus as defined in cLaim 8 inwhich said heating device comprises a tube-like duct for said materialwhich has a widening cross-section; and supply channels for the steamwhich open substantially perpendicularly into the duct.
 11. Apparatus asdefined in claim 8 in which said applicator is a cylinder.